/*
 * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
 * The software in this package is published under the terms of the CPAL v1.0
 * license, a copy of which has been included with this distribution in the
 * LICENSE.txt file.
 */
package org.mule.runtime.config.spring;

import org.springframework.beans.factory.parsing.FailFastProblemReporter;
import org.springframework.beans.factory.parsing.Problem;
import org.w3c.dom.Element;

/**
 * A very simple extension to {@link org.springframework.beans.factory.parsing.FailFastProblemReporter} that intercepts errors
 * related to missing definition parsers to give a more helpful message. In the future we may want to replace this by something
 * more sophisticated that allows different problems to be resolved by different "pluggable" components...
 */
public class MissingParserProblemReporter extends FailFastProblemReporter {

  public static final String NO_PARSER_PREFIX = "Cannot locate BeanDefinitionParser";

  @Override
  public void fatal(Problem problem) {
    if (isMissingParser(problem)) {
      problem = extendProblemDetails(problem);
    }
    super.fatal(problem);
  }

  protected boolean isMissingParser(Problem problem) {
    // Spring doesn't give us much useful data here - parseState and rootCause are null
    String message = problem.getMessage();
    return (null != message && message.startsWith(NO_PARSER_PREFIX));
  }

  protected Problem extendProblemDetails(Problem problem) {
    try {
      String element = ((Element) problem.getLocation().getSource()).getLocalName();
      String namespace = ((Element) problem.getLocation().getSource()).getNamespaceURI();
      String message = "The element '" + element + "' does not have an associated Bean Definition Parser."
          + "  " + getMissingModuleOrExtensionMessage(namespace);
      return new Problem(message, problem.getLocation(), problem.getParseState(), problem.getRootCause());
    } catch (Exception e) {
      // fall back to previous message
      return problem;
    }
  }

  public static String getMissingModuleOrExtensionMessage(String elementName) {
    return "Is the module or extension associated with " + elementName + " present on the classpath?";
  }

}
